The configuration of some printers can be changed during printer operations without power cycling the printer. The printer firmware may track such changes and automatically update configuration information on the printer's user interface, but these "run time" changes are not automatically known to accessories attached to the printer. It can be important for some accessories to know the present configuration of the printer, particularly for an accessory that also has a user interface that displays configuration information. The Hewlett-Packard Co. Mopier.RTM. 320, for example, integrates a scanner and a printer to function as a high speed printer and a high speed copier. Display manager firmware in a copy processor ("CP") manages the copier user interface. The CP operates as an accessory to the printer. The contents of several of the copier menus vary based on what paper is loaded in the paper trays and which optional devices (e.g., paper trays, output bins and stapling devices) are installed on the printer. For example, the user may change the paper in one of the paper trays from letter size to A4 size. Sensors in the paper tray make this change known immediately to the printer. It is desirable that this change also be known to any attached accessories and reflected immediately on the user interface for those accessories, including the copier display of the Mopier.RTM. 320 illustrated in FIGS. 3-5. In FIG. 4, the copier menu indicates that letter size paper is installed in Tray 2. When the letter size paper in Tray 2 is replaced with A4 size paper, the copier menu should be updated as shown in FIG. 5.